# Why do bridges freeze before the rest of the road?

**URL:** <https://boards.straightdope.com/t/why-do-bridges-freeze-before-the-rest-of-the-road/96909>\
**Category:** Factual Questions\
**Created:** [December 4, 2001, 10:20pm UTC](https://boards.straightdope.com/t/why-do-bridges-freeze-before-the-rest-of-the-road/96909 "2001-12-04T22:20:41Z")\
**Posts on this page:** 1\
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**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\
**Post date:** [December 4, 2001, 10:22pm UTC](https://boards.straightdope.com/t/why-do-bridges-freeze-before-the-rest-of-the-road/96909/2 "2001-12-04T22:22:26Z")

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Because the road is protected in part by the Earth below it, and a bridge is chilled by the air passing over it on both the top and the bottom of the surface.

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